Organic light emitting diode (OLED) as a new display technology which is become a mainstream of display industry trends. Comparing to Liquid Crystal Display (LCD), OLED has number of advantageous such as low power consumption, fast response speed, wide view angle, wide color gamut, bendable. However, lifetime and luminous performance are always a technical challenge of the OLED. Please refer to FIG. 1. FIG. 1 is a lifetime curve schematic view of an organic light emitting diode of prior art. Shown as FIG. 1, with increases the using time (Time) of the OLED (value of horizontal axis of FIG. 1), the ratio (L/L0) of the currently brightness (L) and initially brightness (L0) of the OLED is greatly decreasing (value of vertical axis of FIG. 1). It is said that the brightness of the OLED is fast decay within the using time, and causes poor lifetime and luminous performance of OLED.
The principle of OLED emitting is: the electrodes and holes are respectively injected by cathode and anode, and transfer to the emission layer, and composited to exciton in the emission layer, and the exciton emitting by radiative transfer (at this time, the electrodes and the holes are called carrier). Analyze the reason of the technical challenge of OLED according to the principle above, each of functional layers of the OLED is organic small molecular materials, and exist in traps of different depth. Wherein, the carriers bonded by the shallow trap could be released by joule heating effect, and the carriers bonded by the deep trap is hard to get rid of, and while the bonding carriers (here is called polaron) is contacting with the triplet state carriers which has longer lifetime, the energy of the polaron will greatly increases and caused the molecular bond broken. The polaron molecular bond broken causes the molecular structure of the bonding carriers changed such that effects lifetime and luminous performance of OLED.
In order to solve the problem above, it could improve two aspects to emitting material and device structure. However, developing new emitting material needs to experience design, synthesis, purification and validation stages, the development period is long and the yield of material is low such that hard to achieve mass produce. Therefore, this invention is improving form the device structure, provides a new organic light emitting diode and a display device has organic light emitting diode; it could effectively improve problem of lifetime and luminous performance of OLED.